1. Field of the Invention
The present invention relates to a spline engagement structure for coupling an inner joint member with a shaft of constant velocity joints used in automobiles and various industrial equipment.
2. Description of the Related Art
In conventional constant velocity joints for a driving system or the like of automobiles, an inner joint member and a shaft are engaged detachably, and a structure for preventing the shaft from coming off is employed for reduction of the maintenance man-hours for replacement of boots or the like. In this structure, a groove is formed at an end face of the shaft, a retaining ring is provided in this groove, and the shaft is engaged with a contacting face being formed on the inner joint member by means of elastic expansion of the retaining ring. A corner is provided on the contacting face to interfere with the retaining ring when the shaft is pulled out, and disengagement is performed by radially contracting the retaining ring by a component force of the interference force with the retaining ring (see Japanese Unexamined Patent Publication No. 08-68426, Japanese Utility Model Publication No. 64-5124).
There is a demand for a structure for connecting a shaft and an inner joint member so that they cannot be disassembled once built.
A structure according to Japanese Unexamined Patent Publication No. 08-68426 is such that a retaining ring is provided at a non-end face side of a shaft and a groove for inserting a tool for contracting a retaining ring is provided at an end face of an inner joint member, thereby allowing assembly and disassembly. However, this mechanism requires much time and forming the tool engagement groove on the inner joint member is expensive.
Further, Japanese Utility Model Publication No. 64-5124 discloses a structure for contracting a retaining ring thereby allowing a shaft to be pulled out. The publication, however, does not show how to manage an angle of a groove in a sidewall for effecting two types of configurations where one allows a shaft to be pulled out and the other does not.